objective-c: If an ivar is (1) the first ivar in a root class and (2) named `isa`,

then it should get the same warnings that id->isa gets. // rdar://11702488


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158938 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 1 deletions

diff --git a/lib/Sema/SemaExprMember.cpp b/lib/Sema/SemaExprMember.cpp
index 22b23150d1..d5e83ce8ae 100644
--- a/lib/Sema/SemaExprMember.cpp
+++ b/lib/Sema/SemaExprMember.cpp
@@ -1149,7 +1149,20 @@ Sema::LookupMemberExpr(LookupResult &R, ExprResult &BaseExpr,
                                 ObjCImpDecl, HasTemplateArgs);
       goto fail;
     }
-
+    else if (Member && Member->isStr("isa")) {
+      // If an ivar is (1) the first ivar in a root class and (2) named `isa`,
+      // then issue the same deprecated warning that id->isa gets.
+      ObjCInterfaceDecl *ClassDeclared = 0;
+      if (ObjCIvarDecl *IV = 
+            IDecl->lookupInstanceVariable(Member, ClassDeclared)) {
+        if (!ClassDeclared->getSuperClass()
+            && (*ClassDeclared->ivar_begin()) == IV) {
+          Diag(MemberLoc, diag::warn_objc_isa_use);
+          Diag(IV->getLocation(), diag::note_ivar_decl);
+        }
+      }
+    }
+    
     if (RequireCompleteType(OpLoc, BaseType, diag::err_typecheck_incomplete_tag,
                             BaseExpr.get()))
       return ExprError();